Device and method for producing a selvedge



May 13, 1969 H. SCHAFFEIR DEVICE AND METHOD FOR PRODUCING A SELVEDGE Filed April 10, 1967 Sheet May 13, 1969 H. SCHAFFER DEVICE AND METHOD FOR PRODUCING A SELVEDGE Sheet Filed April 10, 1967 H. SCHAFFER DEVICE AND METHOD FOR PRODUCING A SELVICDGE Sheet 5 May 13, 1969 Filed April 10, 1967 of 5 y 1969 H. SCHAFFER 3,443,602

DEVICE AND METHOD FOR PRODUCING A SELVEDGE Filed April 10, 1967 Sheet 4 of 5 y 3, 1969 H. SCHAFFER 3,443,602

DEVICE AND METHOD FOR PRODUCING A SELVEDGE Filed April 10, 1967 Sheet 5 'of 5 United States Patent US. Cl. 139-122 9 Claims ABSTRACT OF THE DISCLOSURE A device for producing a selvedge on a weaving machine, which comprises a movable gripper means provided with a suction tube having a suction orifice at its forward end by which the end portions of weft threads projecting from the shed are successively seized by a sucking action, the tube being moved between the outer warp threads and through the interior of the opened shed towards the projecting end portions and back again to thereby draw the seized end portions, successively, into the shed substantially without fouling or tearing the adjacent warp threads. A method for producing selvedge is also disclosed.

This invention relates to a device and method for producing a selvedge on a weaving machine, and in particular to a device having means for seizing end portions of weft threads projecting out of the shed and for drawing the seized end portions into the shed substantially without fouling or tearing of the adjacent warp threads.

In weavingby the single weft method, i.e. in a method in which each..weft thread is measured in advance as to its length and then inserted into the shed, it is known to form a selvedge by drawing a weft thread end projecting from the shed into the shed after the shed has been changed. In the known method, this operation is performed by means of a hook which penetrates the warp threads in their outer zone, moves through the shed, grips the weft thread end and then moves back again. This operation has the disadvantage that the backward moving hook often fouls the warp threads and can even tear them. Also to ensure that the weft thread end is taken up by the hook, relatively great accuracy is needed in positioning the thread relative to the hook. These disadvantages are avoided by the present invention.

Thus, this invention contemplates a device for producing a selvedge on a weaving machine, which comprises a movable gripper means provided with a suction tube having a suction orifice at its forward end by which the end portions of weft threads projecting out of the shed are successively seized as the result of a sucking action, the tube being moved towards the projecting end portions and back again between outer warp threads and through the interior of the opened shed to thereby successively draw the seized end portions into the shed substantially without fouling or tearing the adjacent warp threads.

The invention will be better understood by reference to the accompanying drawing in which:

FIGURES 1 to 4 show one embodiment of the device of the invention positioned on a weaving machine at different operating stages for forming the selvedge; and

FIGURE 5 shows a plan view of a sample of a selvedge produced by the present invention.

In all the figures, the same reference numerals are used to indicate like parts.

FIGURE 1 shows a part of the sley 31 of a weaving machine. The sley carried a reed 15, used for beating up the drawn-in weft threads. Above the sley 1 are positioned the warp threads 9 forming the upper part of a shed and the warp threads 10 and 11 forming the lower part of the shed. Threads 11 comprise presser warp threads which are separately controlled and in this embodiment are shown as forming the outermost threads of the lower warp sheet. The resulting fabric is designated by the reference numeral 18. Connected to the weaving machine is a device or an arrangement which includes a shaft or rod 32 displaceable in its longitudinal direction. Along a substantially horizontal axis. The longitudinal displacement of this shaft is achieved by means of a lever system comprised of elements 37, 33, 36, and 34. This system is actuated by the rod 35. The rod 35 is moved upwards and downwards by means of an eccentric (not shown). A pivoting movement of the lever 34, in turn, causes a pivoting movement of the lever 33 connected to the shaft 36. The rod 37, extending into a slot in the connecting element 17, causes the shaft 32 to be displaced in the axial direction. Connecting element 17 and the shaft 32 are firmly connected to each other. The shaft 32 is also pivotable or rotatable about its longitudinal axis. Rotation of shaft 32 is achieved by a displacement of the pushrod 12 in the axial direction. This displacement is transmitted to element 17 by the bar 16 which engages in a. second slot in the upper portion of element 17. Since element 17 is firmly connected to the shaft 32, reciprocatory movement of the rod 16 causes rotation of the shaft 32. The small tube 26 secured to the shaft 32 is thus also pivoted. This tube is provided with an orifice 27 and is connected through the 28 to a suction apparatus (not shown).

As shown in FIGURE 4, a holding or thread take-up tube 13 serves to seize and hold the end of the weft threads 24 inserted from left to right. In the present case, the weft threads are inserted by means of a gripper shuttle (not shown). At its end facing the reed 15, the holding tube 13 is provided with a narrow longitudinal slot by which the weft thread is taken up from the gripper shuttle and held. In order to obtain a sucking action, the holding device 13 is likewise connected, via the hose 22 with a suction apparatus (not shown). The holding tube 13 can be moved into the shed and out again by axial displacement of the rod 38.

In order to understand the method of operation of the device of this invention, it will be understood that at the operating stage shown in FIGURE 1, a shuttle is located in its non-operative position on the left-hand side of the weaving machine. Immediately before the shuttle had reached this position, it had drawn in the weft thread 14 from right to left. At its right-hand end this thread is connected to the schematically illustrated stock bobbin 20, from which it has been drawn off, having previously been measured out to a prescribed length. The weft thread 14 has already been beaten up by the reed 15 and is woven in by alternation of the shed.

Immediately after the shed has been opened again to bring it to the position shown in FIGURE 1, transverse movement of the push-rod 12 brings about rotation of the shaft 32, such that the suction tube 26 with the suction nozzle 27 moves between the outer warp threads of the lower shed into and through the interior of the open shed and then in the outward direction into the position indicated in FIGURE 1. In order to obtain a favorable movement, the suction tube has a roughly circular, curved, form.

The next stage of operation can be seen in FIGURE 2. At this stage, the shaft 32 is moved, under the action of the movement of the lever system comprised of elements 33, 36, 34 and 35, in the axial direction and, in fact, forwardly with respect to the weaving machine, ie to the left in FIGURE 2. At the same time, the outermost warp threads 11 of the lower shed are moved upwards again by a separate shed-forming device (not shown). The remaining threads 9 and 10 forming the shed are still in their open shed position at this stage of operations. In the meantime, the shuttle is shot from the left side to the right through the shed. At the same time the holding tube 13, used for seizing and stretching out the new weft thread to be inserted, is pushed into the shed by moving the rod 38 in the axial direction towards the middle of the weaving machine.

In the stage shown in FIGURE 3, the suction tube 26 has, in its forward movement, reached the fabric stop. At this moment the already inserted and woven weft thread 14 is cut by the shears 21 (not shown in the other figures). The end of the weft thread projecting from the fabric is seized and sucked up by the suction orifice 27 of the suction tube 26. The suction tube 26 is thereupon drawn back into the shed and emerges from the warp threads. The warp threads 11, already moved back into the upper shed, cause the small end portion of the inserted thread to be momentarily held in the shed upon release from the suction orifice 27. These warp threads find themselves under a certain tension and slide past the end of the suction tube 26 in the plane of the warp threads 9.

The suction tube 26 is shown in its retracted position in FIGURE 4. Also shown is the weft thread 24 freshly introduced from left to right, this thread being held by the holding tube 13. Simultaneously with the closing of the shed, the holding tube 13 is drawn to the right and so pulls the inserted weft thread 24 to the right.

In order to prevent the formed woven selvedge from becoming thicker or appreciably thicker than the fabric, the length of the weft threads 24 inserted from the left are, advantageously, so measured out that they do not quite extend to the selvedge. The length of threads 24 is so measured out that they only extend so far towards the selvedge that their ends coincide approximately with the ends of the inserted thread ends of the threads 14 inserted from right to left. This positioning is shown in FIGURE 5. As in the previous figures in FIGURE 5, the weft threads inserted from right to left are designated by the reference numeral 14, and the weft threads inserted from left to right by the numeral 24. As shown, in this embodiment, the weft threads 24 inserted from the left overlap the end portions of the weft threads 14 inserted from the right, the amount of overlap extending over three warp threads.

By the provision of the threads 11 forming the auxiliary shed, the ends of the threads 24 are pressed downwards out of the fabric and in this position they can readily be cut away. Thus their length can be very precisely defined in the resulting fabric.

Instead of using threads 11 which are subjected to a special shed movement and which belong to the warp threads 10, it is of course also possible to move separately a part of the outermost warp threads from the other shed 9. In this case this part of the threads would be moved downwards directly after the insertion of the tube 26, as shown in FIGURE 1, and would then lie above the tube 26. Upon retraction of the suction tube 26 from the shed, these threads serve to hold the inserted ends of the threads 14 at the moment when the insertion operation takes place and when these thread ends are released from the orifice 27.

What is claimed is:

1. A device for producing a selvedge on a weaving machine wherein weft threads are inserted along a sley into warp sheds and are heat up into a fabric with end portions of the weft threads projecting out from the outer warp threads of the sheds, said device comprising a moveable gripper means having a suction tube with a suction orifice at its forward end for separately and successively seizing an end portion of each of the weft threads projecting from the sheds by a sucking action, said suction tube having a pivoting motion about a substantially horizontal axis and a reciprocating motion along said axis and successively moving between the outer warp threads and through an open shed formed during the weaving operation towards each successive projecting end portion to seize same by said sucking action and then moving back again through the outer warp threads, the end portion of weft thread seized by the said suction tube being held in the open shed by presser warp threads and the outer warp threads of the shed when released from said suction orifice.

2. The device of claim 1 in which a thread-cutting means is positioned adjacent to the shed for successively cutting the woven weft threads whereby projecting end portions of the threads are successively provided adjacent to said suction tube.

3. The device of claim 1 in which said presser warp threads effect an auxiliary shed-changing movement before the suction tube with the end portion of the last beaten up weft thread is moved back between the outer warp threads and before insertion of another weft thread.

4. The device of claim 1 in which said gripper means includes a drive means for imparting motion to the suction tube.

5. A device for producing a selvedge on a weaving machine wherein weft threads are inserted along a sley into warp sheds and are heat up into a fabric, with end portions of the threads projecting out from the outer warp threads of the sheds, said device comprising a moveable gripper means having a suction tube with a suction orifice at its forward end for separately and successively seizing the end portion of each of the weft threads projecting from the sheds by a sucking action, the tube being moved between the outer warp threads and through an open shed formed during the weaving operation, towards each of the projecting end portions and back again to thereby draw each seized end portion successively into the open shed substantially without damaging adjacent warp threads, said suction tube being of substantially curved configuration over its length to allow it to pass through the outer warp threads, and said suction tube being adapted to pivot about a substantially horizontal axis which extends parallel to the warp plane and to reciprocate along said axis towards the loom front.

6. A method for producing a selvedge on a weaving machine wherein weft threads are inserted along a sley into warp sheds and are heat up into fabric, with end portions of the weft threads projecting out from the outer warp threads of the sheds, which comprises separately and successively seizing the end portion of each of the weft threads projecting from the sheds with a suction tube having sucking action, effecting a separate auxiliary shed-changing movement with a plurality of presser warp threads whereby said suction tube is positioned between the presser threads and outer warp threads of an open shed and thereafter moving the seized portion of said weft thread back through the outer warp threads whereby the end portion of weft thread seized by the sucking action is drawn-in and held in the open shed between the presser threads and the outer warp threads when released by said sucking action.

7. The method of claim 6 in which said presser warp 5 threads comprise approximately the five outermost warp threads of one sheet of warp threads that form said open shed.

8. The method of claim 6 which further comprises measuring out the weft threads, that are inserted into the sheds in a direction opposite from that of those seized by said suction tube, to such a length that their ends on the side towards which they are inserted overlap a few warp threads with the drawn-in end portions of the weft threads inserted from the other side of the loom.

9. The method of claim 8 in which the overlapping takes place over three warp threads.

6 References Cited UNITED STATES PATENTS HENRY S. JAUDON, Primary Examiner.

US. Cl. X.R. 

